Lab 1 Flashcards
Step 1: Ask a Question
What is an indepent variable?
The essential componenet of the phenomenon that is manipulated by the investigator
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What is a dependent variable?
The response to the manipulation.
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What is the observed variable?
The variable we are interested in studying to see whether it has an effect on the dependent variable, however the observed variable cannot be experimentally manipulated.
It involves mutually exclusize groupings that can be identified by name and may or may not have an order.
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What is the comparator?
A group or condition that provides a point of comparison so the research knows if the independent/observed variable influenced the dependent variable.
Step 1: Ask a Question
What is an experimental study?
In an experimental study, the comparator will typically be a baseline condition, a control group, or a control condition.
Step 4: Test the hypothesis
What is a descriptive study?
Descriptive studies involve collecting infromation without any manipulation of the subjects.
- there is no indp variable
What are the 7 steps of the scientific method?
- Ask a question
- Perform background research
- Construct a hypothesis
- Test the hypothesis
- Analyze the data and draw a conclusion
- Reflect on the results
- Communicate the results
Step 3: Construct a hypothesis
What is a hypothesis?
What are the different types?
The hypothesis is the predicted result of the experiment and expected answer to the research question.
- Directional hypothesis: proposes the dependent variable will incr or decr when the indp variable is changed.
- Non-direction hypothesis: proposes the 2 variables are related
Step 3: Construct a hypothesis
What are the 4 components of a well-constructed hypothesis?
- Indp variable being manipulated
- Depd variable being measured
- Comparartor group/condition
- Population being studied, including key subject characteristics
Step 4: Test the hypothesis
What is an experimental study?
An intervention of treatment is intentionally introduced and a result or outcome is observed.
Step 4: Test the hypothesis
What is a case study?
Descriptive
1-2 instances of an observed phenomenon
Step 4: Test the hypothesis
What is a cross-sectional study?
Descriptive
A random subset of a population is sampled to observe the occurrence of a phenomenon
Ex: samping incoming CU freshman to determine what percentage are smokers
Step 4: Test the hypothesis
What is a longitudinal study?
Descriptive
A group of subjects is followed over time to observe how a variable changes
Step 4: Test the hypothesis
What is a retrospective study?
Descriptive
A search is made for a relationship between a current phenomenon and another that occured in the past to examine whether exposure to a suspected risk or protective factor led to an outcome
Step 4: Test the hypothesis
What is a randomized, controlled study?
Experimental
Subjects are randomly assigned to either an experimental OR control group
Step 4: Test the hypothesis
What is a pre/post study?
Experimental
Depd variable is measured in each subject before the manipulation (baseline), and then measured again one time after the manipulation
Step 4: Test the hypothesis
What is a time series study?
Experimental
A depd variable is measured in each subject before the manipulation (baseline), and then measured again multiple times after the manipulation to observe how the depd variable changes over time
Step 4: Test the hypothesis
What is a crossover study?
Experimental
Subjects are divided into different groups, with each group receiving all treatments, but in a different order
Step 5: Analyze the data and draw a conclusion
What is a null hypothesis?
What happens if there is significance difference?
If you are testing the null hypothesis than the results being compared are NOT different. If you find a statistically significant difference between the results being compared, you reject the null hypothesis.
Meaning the manipulation does appear to influence the depd variable.
Step 5: Analyze the data and draw a conclusion
What is the p-value?
What does a small p-value indicate?
The p-value indicates the probablity the results occured by chance alone and are not different.
A small p-value (smaller than alpha, i.e. p<0.05) means the null hypothesis is rejected.
Step 5: Analyze the data and draw a conclusion
What is a chi-square test?
Used to compare whether the observed frequency of a characteristic in a sample matches the expected distribution in another group.
Step 5: Analyze the data and draw a conclusion
What is a t-test?
What are the 2 different types?
A t-test compares two means.
- Dependent (paired) t-test: used to compare mean values from the same subjects are tested more than once or when some other nautral pairing exsits between the measurements
- Independent t-test: used to compare mean valued from two groups that are not related to each other
Step 5: Analyze the data and draw a conclusion
What is an ANOVA test?
What are the 2 different types?
Analysis of Variance (ANOVA) compres more than 2 means.
- Repeated measures ANOVA: used when the mean values are from the same subject evaluated at multiple points
- One-way ANOVA: used when comparingthe mean values from multiple unrelated groups for a single variable.
Step 5: Analyze the data and draw a conclusion
On a graph where are the indp. and depd. variable placed?
The indp variable is placed on the X-axis and the depd. variable is placed on the Y-axis.
Step 6: Reflect on the results
What are the 2 different types of limitations?
- Methodological: due to actual methodology
- Physiological: due to phsyiological factors of subjects
Give an example of hypothesis using average hematocrit levels between males and females.
Hematocrit levels(%) in males will be higher as compared to hematocrit levels (%) in female in healthy college-aged adults living at similar altitudes.
Give an example of a figure caption using average hematocrit between male and female.
Table 1. Average hematocrit (%) values for male (n=8) and female (n=12) Physiology Lab students living in the Boulder area. Data represent average + SD. An independent t-test was used to compare the means with an alpha level of 0.05. * indicates statistical significance at p<alpha as compared to females.
